Holding device.



FIG. 3

J. D, TAYLOR, DECD.

M. E.TAY1.0R, EXEC IX.

HOLDING DEVICE. APPLiCATION FILEDAPR. H, 1914.

Patented Feb. 1,1916,

11 2 SHEETS-*SHEET I.

J. D. TAYLOR, DECD.

M. E. TAYLOR. EXECUTRiX.

HOLDING DEVICE.

APPLICATION FILED APR. 11, 1914.

Patented Feb. 1, 1916 2 SHEETS-SHEET 2.

WITNESSES i. V, Z? I STATES rgiENT O 33. TAYLOR. DECEASED, LATE OF WILKINSBURG, PENNSYLVANIA, BY MARY E. L011, EXECUTRIX; F CHILLICOTHE, OHIO; SAID JOHN D. TAYLOR ASSIGNOR TO 0'9"" SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA. A

-HOLDING DEVICE.

application filed August 28, 1912, Serial No. 717,436. Divided and. this agplication filed April 11,

' 1914. Serial No. 881,263.

on of a holding device Whose action is induction.

csent application is a division of an on flied by the said John D. Taylor ii 52.. Serial No. 717 ,436, ior

devices embodying the present i are p2. wnlarly' Well adapted for in railway signals to hold the semaphore .inst the action of gravity or other biasforce, although they are not limited to this particniar adaptation.

One form of holding device embodying the invention will first be described and the novel features thereof then pointed out in ciaims.

In the accompanying drawings, Figure '1 is a view showin in front elevation one .i'orin of hoiding device embodying the invention. iiig. 2 is a sectional view on the planes indicated by line TI -II in Fig. 1, looking in the direction of the arrows. Fig. is view on the plane indicated by the hne III-TH in Fig. 1, looking; in the direction of the a ows.

fdimilar rein .ice' characters refer to simiiar parts in each of the several views.

first to Figs. 1 and 2, the ole vibe here shown comprises a stator or pri-' mcry member and rotor or secondary member 48. The stator or primary member 29 comprises a plurality of laminations of sr'ormer iron suitably clamped together *een two end plates 29" of similar mateand is formed with a plurality of inwarc y projecting pole-pieces 50, here shown being eight in number. This str Jor member-is provided with a winding 31 comprising coil on each. pole-piece,

which winding 31 may at times be supplied with alternating current from agenorator G. the circ; it being controlledby' -a prises a plurality of rings tl'iin transformer iron having embedded therein jilm rality of rods 52 of electrdconduc terial, preferably copper, the

rods preferably being eqnai to tne nnmber ofpole-pieces 50. These rods are eiec'r'o cally connected by end rings ecctrd conductive material,="also preferably oi; per. It will be seen,. therefore, that the rotor comprises a plurality of closed eiectric circuits and may therefore be termed a squirrel-cage rotor. The rods are fixed securely in the end rings 30 so that they serve also as rivets to clamp the laminations together. As here shown, the stator or primary member 29 is stationary being fixed in an inclosing box 37, and the rotor Patented Feb. 1, 1916.

or secondary member is carried by a spide' 12 which is keyed to a Spindle 15 su a ly mounted to rotate in bearings 11 in the 37, only one of which bearings is shown the drawings.

It will be seen from the fJr-egoing the holding device is a transformer detice having a fixed primary member E39 and a rotatable secondary member 48.

The spindle 15 may be cany movable member which it desired should be. held in. one or more given tions against the action of a force tending to cause it to move. For example. the movable member may be a railway signal scmaphore as shown in the application. of John D. Taylor, Serial No. 717,436 of which'the present application is a division. This is indicated diagrammatically in Fig. 2 of the the present drawings, in which S is a semaphore which is biased by gravity to the denger position and which may be moved to one or more other positions, such as caution and clear, by an electric motor M. In the construction here indicated it is understood that While the mot-c2: M moving the 561mb phore away from the danger position the wmding 31 is deenergized so that the hotel'- ing device Offers no opposition movement, but that when the semaphore reaches the position in which it is to be held the motor is deenergized and thewinding 31 is energized by the closure of contact shown in Fig. 1.

The holding action oii'the device is due to the fact that when the winding 31 is energlued by alternating current the magnetic illun from the polopieces 50 flowing-through rotor i8 tends to hold the latter in such .ition that the rods 52 are opposite the idle points of the pole-pieces, because in s position no current is induced in the rods. Considerable force is required to move the rotor from this position, and this force increases as. the rods approach the edges of the pole-pieces. The parts are so adjusted and proportioned that the force acting on the semaphore S is less than the force required to drag the rods 52 beyond the edges or the pole-pieces.

it is sometimes desirable that the stator member 29 be employed to control an armatore which operates one or more circuit controlling contacts or other apparatus; this function may be accomplished in the following manner: A. slot 51 is cut through the stator between two adjacent pole-pieces 5 and 50 and a movable armature 461s mounted opposite the gap thus formed.

This armature is or soft iron, and is proferably formed of a plurality of laminations hold together by a clamp M which is riveted to a lever 4:5 pivotally mounted in trunnion screws m a box 39 attached to the box 37. The laminations oi armature 4&6 are parallel with the plane of the paper in Fig. 1, and are obscured by the clamp 44 in Fig. 3, hence they are not shown in the drawings. Fixed to the lever 45 by means of insulation studs ii are two contact fingers 4:0 and 41, the former of which makes contact with a fixed block 42 when the armature is attracted to the stator, and the latter of which makes contact with a hired plate d8 when the armature falls away from the stator. The armaturc 1-6 is prevented from actual contact with stator 29 by a studfixed in the end of lever 45, which stud engages with a stud 32 fixed in box 37.

l i ith the slot ,51 in the stator, it is evident that the flux which otherwise would flow in the circuit including pole-pieces and 50* and the portion of the stator'joining these pole-pieces, would now tend to flow from the base of one of these pole-pieces through almost the entire circumference of the stator to the base of the other pole-piece, and vice-verso, so that little or no flux would tiow through the armature 46. To prevent this, that is, to force some of this flux to flow through the armature 46, a low-resistance closed electric circuit is placed on each po e piece 58 and 50, each of which circu comprises two copper rods 53 passing niiosoo through the stator and electrically connected on each face of the stator by a copper plate Each of these circuits is so placed that its plane is parallel to the normal direction of the magnetic flux in the pole-piece, hence they do not interfere with the flux passing from these pole-pieces through the rotor 48.

They do, however, force part of this flux to return through armature d6, and this flux causes the armature to be raised toward the stator. This action of the closed circuits is due to the fact that the flux in the adjacent halves of pole-pieces 50 and 50* would, if

1t were to return through the unbroken part or the stator, have to pass through the lowresistance circuits on these pole-p1eces, but

these circuits offer high impedance to the therein Within the scope of the appended claims without departlng from the spirit and scope of the invention.

Having thus described the invention, what is claimed is:

1. A holding device comprising a stator, a single phase winding for said stator, and a squirrel-cage rotor having the same number of rods as the stator has poles. 7

2. A holding. device comprising a stator, a single phase winding for said stator, and a rotor having the same number of closed electric circuits as the stator has poles.

3. A holdin device comprising a stator, a single phase winding for said stator, and a rotor with'a short-circuited winding having the same number of poles as the stator;

El. A holding device comprising a stator having an energizing winding, a rotor, a

gap in the stator, an armature adapted to bridge said gap, and means for causing part of the magnetic flux in the'stator to pass through said armature.

5. In combination, a'subst:mti.ally ringshapcd member of magnctizable material having pole-pieces and having a gap between two of said pole-pieces, windings on said pole-pieces, an armature adapted to bridge said gap, and means associated with said ring-shaped member for causing part of the flux from the pole-pieces adjacent said gap which would otherwise return through the unbroken portion of the member to flow through the armature.

6. ){n combination, a. substantially ringshaped member of magnetizable material having pole-pieces and having a gap between two of said pole-pieces, windings on said pole-pieces, an armature adapted to bridge said gap, and a circuit of electroconductive material on one of the pole-pieces adjacent said gap, said circuit being so disposed that its plane is substantially Parallel to normal direction of magnetic ux in the pole-piece, whereby a portion of the flux fronrsaid adjacent pole-piece which would otherwise return through the unbroken part of the member is-caused to pass through said armature.

7. In combination, a substantially ringshaped member of magnetizable material having pole-pieces and having a gap between two of said pole-pieces, windings on said pole-pieces, an armature adapted to bridge said gap, and a circuitof clectro-conductive 1:; material on each of the pole-pieces adjacent said gap, each circuit comprising conductors extending through the stator and other con- 

